Free Online JSON to CSV Converter - Convert JSON to CSV and CSV to JSON in Your Browser
Fast, private two-way conversion between JSON and CSV. Flatten deeply nested schemas, auto-detect delimiters, preview live tables, and stream heavy files up to 100MB+ without uploading a single byte.
Why Use TrueJSON to Convert JSON and CSV Online?
When developers, data analysts, and researchers need to convert JSON to CSV online free or parse spreadsheet tables with CSV to JSON, privacy is paramount. Traditional conversion websites upload your proprietary data, customer records, database dumps, and API responses to unknown backend servers where your secrets could be logged or stored.
TrueJSON is built on a modern privacy-first philosophy: ZERO backend processing. All data transformation, syntax parsing, and table rendering execute locally inside your web browser using high-performance JavaScript and PapaParse—the industry-standard in-browser CSV parser. No files are ever sent to remote servers or third-party cloud infrastructure.
Intelligent Nested JSON Flattening
Real-world JSON payloads rarely conform to simple flat key-value pairs. APIs from Stripe, Shopify, GitHub, and Firebase return deeply nested objects and arrays. TrueJSON uses standard dot notation (e.g., user.address.city or billing.card.last4) to cleanly flatten hierarchical trees into distinct CSV columns, with arrays of primitives preserved seamlessly.
Web Worker Streaming for Heavy Files
Most web-based converters lock up the browser tab and trigger "Page Unresponsive" dialogs when opening multi-megabyte files. For files larger than 5MB, TrueJSON automatically spins up dedicated Web Workers to parse and stream records in the background, reporting live progress percentages while keeping your interface ultra-responsive.
Interactive Table Preview & Delimiter Support
Inspect your generated tabular dataset instantly with an interactive 50-row live preview table before downloading. Support for all international delimiters—including commas (,), semicolons (;), tabs (\t), and pipes (|)—ensures full compatibility with Microsoft Excel, Google Sheets, Pandas, and PostgreSQL.
100% Client-Side Privacy: The True Difference
When working with sensitive analytics logs, GDPR-regulated user databases, or internal financial spreadsheets, uploading your files to third-party cloud servers poses unacceptable compliance and security liabilities. At TrueJSON, every single byte is parsed in your device's RAM. You can turn on Airplane mode or inspect your browser DevTools Network tab—zero data is transmitted across the wire.
How to Convert JSON to CSV in Seconds
Convert raw API payloads, database exports, and CSV logs into ready-to-use files in three simple steps.
Paste or Drop Your File
Paste JSON or CSV directly into the monospace editor, or drag and drop a .json or .csv file. Click "Sample Data" to test with rich sample objects.
Configure Options
Toggle nested object flattening, pick your preferred delimiter (comma, semicolon, tab, pipe), or switch between JSON array and keyed object formats.
Preview & Download
Review the 50-row live table preview or formatted code block. Click "Download .csv" or "Download .json" to save the file instantly to your device.
Answers to Common JSON & CSV Questions
Learn more about how our browser-based PapaParse engine handles complex nested keys, large datasets, and data privacy.
Ready to Convert JSON and CSV Privately?
No registration, no rate limits, and zero server uploads. Convert your developer payloads and datasets with complete confidentiality.